Question

5. How many molecules of sulfuric acid are contained in 14 mmol of sulfuric acid? How manyatoms of oxygen are in this sample?

Answer 1

(a)Molecules of Sulphuric acid -

1 mole of H2SO4 contains 6.022x10^23 molecules

14mmol of H2SO4 will contain = x molecules ....(do a cross multiply)

Therefore x = 6.022x10^23 *14 /1000...( divide by 1000due to millimoles )

=8.43x10^21 molecules.

• This means that 14mmol H2SO4 contains 8.6x10^21 molecules.

(b)Atoms of oxygen

• H2SO4 compound has 4 Oxygen atoms.

we know that :

1 mole H2SO4 : 6.023x10^23 atoms

4 mole Oxygen atoms in H2SO4 : x .....................( cross multiply)

x atoms = 4*6.023x10^23 =2.41x10^24

14/1000moles H2SO4 will contains 2.41x10^24*14/1000

= 3.37x10^22 atoms

• This means that 3.37x10^22 atoms of oxygen are contained in this sample.